The invention relates to a reflector lamp unit comprising:
a glass reflector body provided with a concave reflecting surface having an optical axis, and around the optical axis a neck with a free-end portion;
an electric lamp with a lamp vessel which is sealed in a gastight manner and in which an electric element is arranged and connected to current conductors which issue to the exterior from a seal of the lamp vessel;
a metal sleeve fastened around the neck of the reflector body, which sleeve has projections which face away from one another and extend transversely to the optical axis,
the electric lamp being secured in the neck and the current conductors each projecting from the neck and the sleeve to the exterior with a respective free end so as to form contact pins.
Such a reflector lamp unit is known from EP 0 367 323-A2. The metal sleeve in this case has the object of providing the unit with a profiled outer surface at which a lampholder, in which the unit is accommodated, can grip the unit by means of resilient retention means. It is prevented thereby that a lampholder is capable of holding the unit by the contact pins only, which provides too uncertain a retention of the unit.
GB 2 153 986-A discloses the provision of grooves in the neck of the reflector body, into which retention means can engage. A disadvantage of this is, however, that there is too wide a spread as regards the dimension of the neck in order to safeguard a good retention.
The reflector lamp of EP 0 367 323-A2 has the advantage that the metal sleeve has the profile with which retention means can cooperate and that the sleeve can be readily manufactured with narrow dimensional tolerances. A disadvantage is, however, that the sleeve in the known unit is fixed around the neck with cement and that its mounting as a result is time-consuming and accordingly expensive. Cement does render it possible to fix the sleeve immovably around the neck in spite of the dimensional variations in the latter. In this unit, the metal sleeve forms an extension of the neck. A disadvantage of this is the risk that the sleeve short-circuits the contact members of a lampholder, which need not be recessed in the case of lampholders for low-voltage lamps.